Buttonhole attachment for sewing machines



N. T. ALMQUIST BUTTONHOLE ATTACHMENT FOR SEWING MACHINES Filed June 2, 1952 F eb. 22, 1955 2,702,515

2 Sheets-Sheet l .im 3, a@ 4f @345 44 /7 ./a f5 AT ORNEYS N. T. ALMQUIST BUTTONHOLE ATTACHMENT FOR SEWING MACHINES Filed June 2, 1952 Feb. 22, 1955 2 Sheets-Sheet 2 INVENToR. /\//.5 I AL/v/QU/J T TOQNEYS United States Patent O BUTTONHOLE ATTACHMENT FOR SEWING MACHINES Nils T. Almquist, New Britain, Conn., assignor of fifty per cent to Raymond Engineering Laboratory, Inc., Middletown, Conn., a corporation of Connecticut Application June 2, 1952, Serial No. 291,151 i 25 Claims. (Cl. 112`77) This invention relates to buttonhole attachments for sewing machines, and pertains more particularly to an improved attachment of this type in which the button for which the hole is to be made may serve as a template.

Accordingly, an object of the invention is to provide a buttonhole attachment in which the pattern of movement of the fabric beneath the needle bar of a sewing machine may be controlled by the button for which the hole is intended.

Another object of the invention is to adjust simultaneously the various mechanisms comprising the buttonhole attachment in direct correspondence with the size of button to be used.

A more specific object is to provide an adjustable buttonhole attachment in which the ultimate length of buttonhole, the width of stitching, and the spacing between stitches are all governed by the particular size of button used as a template.

Inasmuch as certain prior art buttonhole attachments require various individual adjustments to be made, the invention has for an object the provision of a buttonhole attachment which completely obviates having to perform these independent manipulations. Also, it is within the purview of the invention to eliminate the necessity of purchasing a number of guide members, one for each size hole, and thereafter having to select the correct one each time the hole size is to be changed.

A further object of the invention is to avoid completely the need for making any measurements or calculations in the forming of properly sized buttonholes.

A still further object of the invention is to provide a buttonhole attachment that will automatically increase the size of the buttonhole for thicker buttons.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplied in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the drawings: 4

Figure 1 is an elevational view of one embodiment of my buttonhole attachment, the casing being shown in section to expose the various parts;

Fig. 2 is a plan view taken in the general direction of line 2-2 of Fig. 1;

Fig. 3 is a view taken in the direction of line 3-3 of Fig. l;

Fig. 4 is a view taken in the direction of line 4--4 of Fig. l;

Fig. 5 is a sectional view taken in the direction of line 5--5 of Fig. 2;

Fig. 6 is a fragmentary view of a slightly modified version of the invention; and

Fig. 7 is a view taken in the direction of line 7--7 of Fi 6.

eferring in more detail to the drawings and specically to the embodiment exemplified in Figs. l-5, the buttonhole attachment there depicted, which is generally denoted by the reference letter A, includes a base plate 10 and a detachable cover 11 therefor held in place by a screw 12 threadedly engaged with a stationary post 13. Attaching means 14 fixed to one end of the base plate 10 permits ready securement of the device to the presser bar of a sewing machine.

In using the attachment A, the conventional feeding mechanism of the sewing machine is rendered ineffectual "ice by use of a cover plate (not illustrated). Instead, the feeding of the fabric is 'accomplished by means of a serrated presser foot 15 carried at one end of a feed blade 16. In order to effect stitching of that portion of the fabric in which the buttonhole 1s to be formed, it is' apparent that the presser foot 15 must follow a rather complex and tortuous pattern involving longitudinal, transverse, and oscillating movements.

While the foregoing movements are each interrelated, the rst portion of the description will deal chiefly with the mechanism for producing the longitudinal movement, that is, from right to left as viewed in Fig. l. This particular mechanism comprises an actuating lever 17 bifurcated at one end 18 for engagement with the needle bar of the sewing machine and provided at its other end with cam finger 26. The lever 17 is pivotally mounted intermediate its ends to a pin 21 supported between a pair of standards 22 and 23 forming a generally U-shaped frame 24 when viewed from one end, the frame being secured in any suitable manner to the base plate 10.

An upstanding shaft 25 extends from the base plate 10 upwardly through a bridging portion 26 of the frame 24. A one-way clutch designated generally by the reference numeral 27 is operativelyvassociated with the shaft 25 and conventionally includes a clutch disc 29 xedly carried by the shaft for rotation therewith, a chorded dog element 30 and a retaining plate 31 embracing both the disc 29 and dog 30. The dog element 30 is actuatable by a rocker arm 32 loosely encircling the shaft 25 and biased in a clockwise direction, as viewed in Fig. 2, by means of a tension spring 33 having one end thereof anchored to the frame 24. The end of the rocker arm 32 lying opposite the spring 33 is equipped with an extension portion 34 serving as a follower for the cam finger 20. Thus an upward movement of the bifurcated end 18 of the actuating lever 17 will produce a counterclockwise turning of the shaft 25, whereas an opposite movement will produce no turning.

The intermittent rotation of the shaft 25 by the one-way clutch 27 is converted into rectilinear motion by virtue of a mutilated pinion 3S rotatably carried by the shaft and acting in concert with a rack member 36. The rack 36 is equipped with internally opposed sets of teeth 37 and 39 with blank ends 40 and 41, the blank ends cooperating with the mutilated portion of the pinion 35 to provide a longitudinal dwell at each end of the buttonhole being formed. The teeth 37 of course cause the rack to move to the right and the teeth 39 similarly cause the rack to be moved to the left, inasmuch as the shaft 25 is clutched in a counterclockwise direction. In this embodiment the rack 36 is guided for longitudinal movej ment by a pin 42 anchored to the base plate 10 and engageable in a slot 43 provided in the rack 36.

Obviously, if an attachment of this character is yto be of practical value, provision must be made for adjusting the length of stroke of the feed blade 16 and its presser foot 15, since each buttonhole must be of a size corresponding to the size of button to be accommodated. Accordingly, it is within the contemplation of the invention to use the button itself as a template in forming the hole. To permit the use of the button for accomplishing this end, a stationary jaw element 44 is aixed to the base plate 10 and an opposed, movable jaw element 45 is carried by a longitudinally slidable plate 46. f

The slidable plate 46 is equipped with an upstanding pin 47 adjacent one end thereof, which pin engages a lever arm 49, said arm having a forked end 50 and an opposite finger gripping end 51 intermediate its ends; the arm is pivoted about a pivot pin 52 secured in the base plate 10. In this way the finger end 51 may be manipulated to separate the jaw elements 44 and 45 suiiiciently for the reception therebetween of a button 53 shown in phantom outline in Fig. 2 for which a buttonhole is to be made, aspring 54 having one end anchored to the pin 47 and its other end to the frame 24 to bias the jaw element 45 against the button 53 once finger pressure' has been removed from the portion 51 of the lever ami 49.

Inasmuch as the lever arm 49 assumes a definite angular position in correspondence with the button 53, an ear member 54 is made rigid with the lever member 49, or if desired integral therewith, `so that said ear member will likewise assume a denite position depending on the size4 of button inserted between the jaws. d4. and. 45. The distal end of the ear member 54 has depending therefrom a pin 55 acting as a fulcrum for a link 56, the pin S5 engaging a slot S7 inthe link 56 to electthis purpose. The link S6 is pivotally connected at 59 to thel rack 36 and at 62'3 to a second link 6l which is. in turn pivotally connected at 48 to the, feed blade 16,` suitable pins pro.- vidirig these various pivot points. Thus it will be seen that when a relatively large button, such as the button` 53 is employed as a template, then the pin 5,5 is closerl to the pivot'59 and a fairly large momentarm is provided between this pinA 55 and the pivot 60, thereby producing a relatively large amount of travel of the feed blade` 1,6 for a large size button, theconverse of course being true when a smaller button is, inserted between the jaws 44 and 45. Stated very succinctly, thebutton inserted; between the jaws 441 and 45 determines the length ofthe buttonhole being'formed.

Up to this point the description has been concerned vwith the stroke or distance traveled by the feeder blade 16 and its presser foot l5, nothing as yethaving been said about the. rate of travel o f, this blade te. The rate orV travel is important because a greater numberof total stitchesis necessary for,V along buttonholev than; for a shortone.` Thereforethe invention envisages the utilization of an eccentric carni@ ls 1n1te-dl on the ear member- 5 4in such fashion as` to be; engaged by an adjustable setscrew 63.V carried by the rocker arml 32. Theparticular angular position of the cam 62` will arrest the return movement ofthe rocker` arm-Itl` inaceordancewith the button size, the position ofthe Cam 612 pictured causingan early arrest, which is desired for; relatively large buttonholes since, this limits, the amount the discA 29 of the one-.way clutch 2 7 can belQtated each time the actuating lever 18 makes an upwardstroke. 0f course, the amount of rotation of theclutch disQZS determines the rate of movement of the rack 3,6, andthe rate of movement of the rack in turnv gOYernsthe rate of movement of the feed blade 1,6, inasmuch as the rack and feed blade, are articulatiyely c onneted. by means of the links56 .and 61.

Explained diierently, the feedr blade 1'6- isV moved through one complete cycle from. the right-hand'position showrrto a lefthandpositionand then back to the righthandi position again each time the pinioni` makesA one complete revolution. Since-it is the particularv fulcruming position of the pin 55;. that determines the distance traveled; by the blade 1.6 during the above-mentioned cycle, itis essential for uniformly; spaced stitching that the rate oflongitudinal.advancement of the feed blade -6be-kept constant for a.A constant rate of upand down reciprocation ofthe needle bar of the sewing machine, it being rememberedthatthe actuatinglever 17 s-operatedby said needle bar. In other words7 the feed'blade is to be advanced a givenincremental distance for each strokefof the actuatingn lever; 1.7` irrespective of theparticular position of the pin 55, and thecamZis designed withLthe-proper amount of eoeentricity toelfect this condition. Thusthe word rate inthe sense used in this application may be; dei'nedv as the ratio between the distance the feed blade-161 is movedgandthenumber of strokesmade-by thev` actuating lever 17 (or the needle` bar of thesewing machine-inasmuchzas' the needle han drives the actuating lever in synchrA ,ism therewith), such ratio .being constant to produce uniform stitching for diiferent.lengthbuttonholes.

Considering nowV the meehanisml for` producing the desired degree off-swing of the presser foot in orderto establish the width of the stitching orthe bite as it is sometimes.t er r n ed`,` a cam roll deis rotatably supported on thepin; 2land; is; driven intermittently by a pa-wl 65 and ratchetA 66, the former; beingpivotally carried by the actuating` lever; 1,7 and the latter rotatably carried by.'- the cam roll 64. By means of this arrangement the cam. roll 64iscaused to rotate aprescribed amount each time the: actuating lever'limoves upwardly, thatis, whenthe sew-` ing niacl'lirley isnotystitching, Guided by azig-zaggroove the oscillating motion of the lever 59 to said feed blade and. thence tothe presser foot 1.5. A slot 72 in the base plate 10 permits unrestricted transfer of the movement of the lever 69 to the feed blade, the pin 71 extending therethrough.

Correlation between the degree of bite and the size of button is effected by mounting a pin 73 on the slidable plate 46, the pin extending through a slot 74 in the base plate 10 into engagement with a slot 68 provided in the feed blade 16. As previously explained, the slidable plate 46y supports the jaw 4S. and this of course positions the pin 73 at a sitns governedby the. button size.

For the sake of simplicity in explainingthe part the pin 73 plays in determining the bite of the presser foot 15, let us assume for the moment that thereis no longitudinal movement or advancement of the feed blade i6. Under these assumed conditions it can readily be seen that the nearer the pin 73 is to the presser foot 15, the less the oscillating swing of said. presser foot for a given swing of the pin 71 adjacent the opposite end of the-feed bladeneedle. remains constant for any setting of the pin 73;v

Sliding movement of the feed blade 16 is permitted by incorporatingkinto the feed blade i6 a longitudinal slot 75, to receive the pin 7l. Since the distance-between pin 71 and pivot 73isv constant` during any-- selectedy setting, the angular swing of the presser-'foot lfor a particular position of the pin '73 is maintained constant;

Sofar the foregoingdescription has made no mention of the mechanism for switching the-presser foot l5' 'from-V one side of. the buttonhole to the otherafter a stitching pass. has beenperformed along the first side; To accomplish this necessary result, a two-radius cam-76', cut wtl'r dwell vportions 77, Hand-transitional portions 79; 3S,- the latter portions coinciding-with the blank or dwell ends 4d anddli ofthe` rack 36, .isfiXedi-y mounted onk the shaftl 25 for rotation with said-shaft and havinginl engagement therewith apair of followerelementsY Si and 82 oppositely. disposedat one end of a followerplatc; 83; The follower plate-S-is pivoted about the pin- 52, anddue to' the engagement of theother-end' of the followerplate 83 with the pin 70, it willbeseenthat the rotative position of the cam 76-will` cause the pin 7tl-to be4 movedtol one side or theother of a central position, such transitional movement taking place gradually'ateach end of the stroke of:y the feedblade 16 whenthe portions '79 and Sil are in engagementwiththefollowers Si. and 82. Ink other words, thepin^70-which serves'as therpivotl for the' swivel lever 69.is'caused'to bel positionedflaterally to one side ofthe ultimate buttonhole slit'for: stitching'along one side thereof and to the other side for stitching along the second side during the reverse travel` of the presser foot 15.

Since-the-pin76`is1shifted'in the manner above alluded rotation thereof., Usually the user of the devisev A Will' wish to start. w-itl1-whatJ wiil be, one end'of` the' buttonhole, this serving asV a datum point from which to begin operations. Accordingly, the knob llperrnits the shaft Z5 to` be rotated sufficiently to cause rotation of the pinion 35" into the position illustrated in Fig. 3;,for examplewhich..

places the presser foot. 151 at one. end of, its; stroke and thus the.. fabricengaged. thereby in. apositionibeneath the sewing machine neede for the start. ofa. buttonhole: at the desired location;

A further refinement; of lthe invention notyet, referred'.

to -provideszfori aniincrcasedslengthening of. thebuttonhole for thicker buttons than for thin buttons;y This1isgobviously 'desirable'A in order to permitV faoileinsertion ofijtiie button. through the hole in-v fastening andfunfastening thel fabric to which the button is attached. Therefore, it is within the contemplation of the invention to cant or angle the jaws 44 and 45 as best seen in Fig. 1, so that a thicker button will urge the jaws farther apart than a relatively thin one. Having already explained that the degree of separation of the jaws 44 and 45 determines the length of the buttonhole, it is thought that this feature will be quite readily understood.

The reason for the embodiment pictured fragmentarily in Figs. 6 and 7 is to provide for a more perfect spacing of the stitches on each side of the buttonhole being formed. Inasmuch as the pin 60 of the embodiment just described follows a curvilinear path, as it is constrained to do since the rack 36 travels in a rectilinear path, the longitudinal component of velocity of this pin 6i) will be greatest during the central portion of its swing, that is, when there is little or no transverse component. However, such a course of events will impart an increased velocity to the feed blade 16 with a consequent increase in the stitch spacing.

To obviate the foregoing condition, which in actual practice would probably be objectionable to only the most discriminating user, the modified attachment, designated generally by the letter B, employs a link 85 pivotally connected at one end to the rack 36 by a pin 86 in lieu of the previously employed pin 42 and slot 43, and at its other end to the frame 24 by a pin 87. In this way the rackitself is made to traverse an arcuate path and will shift the link 56 sufficiently to decrease the distance between the pins 5S and 60 during the central portion of the travel of the pin 60, thereby providing the desired amount of compensation not possible with the buttonhole attachment A. Other than that noted, the mechanism of the device B is identical with that of the device A and therefore corresponding parts bear the same reference numerals in both embodiments.

As many changes could be made in the above construction and many apparently widelj, diferent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and speciiic features of the invention herein described and'all statements of the scope of the invention which, as a matter of langauge, might be said to fall therebetween.

I claim as my invention:

l. A buttonhole attachment for sewing machines comprising a pair of relatively movable members, means biasing the members together, means for holding a button between the members to separate the members in accordance withthe size of the button, a feed blade, means for moving said blade including actuating means and a pivoted lever attached at one end to the actuating means and at the other end to the blade, and means associated with one of said button engageable members to vary the moment arm of said pivoted lever in accordance with the relative spacing of said pair of button engageable members.

2. A buttonhole attachment for sewing machines comprising a support, a pair of relatively movable jaw members for engaging a button therebetween, a feed blade, means connecting said blade to the support for oscillating and sliding movement, means attached to the blade at a point spaced from the connecting means for oscillating the blade about the connecting means and means associated with one of said jaw members for varying the position of the connecting means to vary the oscillation of the free end of the blade in accordance with the relative spacing of said jaw members.

3. A buttonhole attachment for sewing machines comprising a supporting plate, a feed blade mounted for longitudinal and oscillatory movement relative to said plate, a driving member movable in a ixed pattern of predetermined length, a mechanical linkage between the driving member and the blade having a settable member for varying the length of movement of the blade responsive to movement of the driving member, a pair of relatively movable jaw members for engaging a button therebetween, and means operatively connecting the settable member to one of the jaw members for adjusting the settable member to produce a length of movement ofthe blade corresponding to the relative spacing of the jawV members. v

4. The structure described in claim 3 in which said jaw members are inclined toward each other to increase said distance for thicker buttons.

5. In a buttonhole attachment for a sewing machine having a needle bar, a support, an actuating lever adapted to engage said needle bar, a one-way clutch actuatable by said lever, a mutilated pinion rotatable with said clutch, a rack member engageable with said pinion, a feed blade, link means articulatively connecting said rack member and said blade, a pair of relatively movable jaw members for engaging a button therebetween, and means interconnecting one of said jaw members with said link means for altering the fulcruming of said link means in accordance with the relative spacing of said jaw members.

6. In a buttonhole attachment for a sewing machine having a needle bar, a support, an actuating lever adapted to engage said needle bar and having a cam at one end, a one-way clutch including an arm actuatable by said cam, a mutilated pinion rotatable with said clutch, a rack member engageable with said pinion, a feed blade, link means articulatively connecting said rack member and said blade, a pair of relatively movable jaw members for engaging a button therebetween, and means interconnecting one of said jaw members with said link means for altering the fulcruming of said link means in accordance with the relative spacing of said jaw members.

7. A buttonhole attachment for sewing machines comprising a supporting plate, an adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade, means mounting the blade for longitudinal and oscillatory movement relative to said plate including a pivot adjustably secured to the plate, drive means including a member movable substantially longitudinally of said plate, articulated link means interconnecting said longitudinally movable member and said feed blade, means interengaging said adjusting member and the pivot for varying the location of the pivot, and means interengaging said adjusting member and said link means for changing the fulcruming of said link means.

8. In a buttonhole attachment for a sewing machiney having a needle bar, a support, an actuating lever adapted to engage said needle bar, a shaft supported by said supf means interconnecting one of said jaw members kwith said link means for changing the fulcrum point of said link means in accordance with the relative spacing of said jaw member.

9. In a buttonhole attachment for a sewing machine having a needle bar, a support, an actuating lever adapted to engage said needle bar and having a cam at one end, a shaft supported by said support, a one-way clutch carried byvsaid shaft and equipped with an arm actuatableby said cam, a rack member provided with two rows of opposed teeth, a mutilated pinion mounted on said shaft for rotation therewith and engageable with said teeth to move the rack in opposite directions, a feed blade, means pivotally and slidingly connecting said blade relative to said support, link means articulatively connecting said rack member and said blade, a pair of relatively movable jaw members for engaging a button therebetween, and means interconnecting one of said jaw members with said link means for changing the fulcrum point of said link means in accordance with the relative spacing of said jaw members.

l0, The structure described in claim 9 in which means l are provided for guiding said rack member in a rectilinear path.

ll. The structure described in claim 9 in which means I gitudinal and oscillatory movement relative to said plate, l means for producing longitudinal movement of said feed blade, including an actuating member movable substantially longitudinally of the plate and adjustableA motion transmitting means between the member and feed blade, a pair of rela-tively movable. jaw members for engaging a button therebetween, means associated with one of said jaw membersand responsive to the relative spacing thereof for adjusting the motion transmitting means, and means associated with one of said jaw members and responslve to the relative spacing thereof for controlling the rate of longitudinal movement of said actuating member.

13. buttonhole attachment for sewing machines comprising a supporting plate, a feed blade mounted for longitudinal and oscillatory movement relative to said plate, means for producing longitudinal movement of saidz feed blade including an oscillatory arm, meansv for limiting oscillatory movement of said arm including a cam, a pair of relatively movable jaw members for engaging a button therebetween, means associated with one of said jaw members and said cam for positioning said cam to control the movement of said arm and thus the longitudinal rate of movement of said feed blade.

14. A buttonhole attachment for sewing machines comprising a supporting plate, an adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade mounted for longitudinal and oscillatory movement relative to said plate, means for moving said feed blade longitudinally including an oscillatable arm, and means including a cam engageable with said arm, said last namedV means connecting with said adjusting member to position said cam according to the position of said adjusting member.

15. In a buttonhole attachment for a sewing machine having a needle bar, a support, an actuating lever adapted to engage said needle bar and having a cam at one end, a shaft supported by said support, a one-way clutch carried by said shaft and equipped with an arm actuatable by said cam, a rack member provided with two rows of opposed teeth, a mutilated pinion mounted on said shaft for rotation therewith and engageable with said teeth to move the rack in opposite directions, a feed blade, means connecting said feed blade relative to said support for oscillatory and longitudinal movement, means connecting said rack member with said blade for transmitting movement from said rack to said blade, a pair of relatively movable jaw members for engaging a button therebetween, and cam means connecting with one of said jaw members and engageable with said arm to control the amount of longitudinal movement of said feed blade in a predetermined ratio with the number of strokes of said actuating arm.

16. A buttonhole attachment for sewing machines comprising a supporting plate, a pair of relatively movable jaw members for engaging a button therebetween, a feedblade, means movable with one of said jaw members for pivotally and slidingly engaging said feed blade, and means for oscillating said feed blade about said pivot.

17. A buttonhole attachment for sewing machines comprising a support, a pair of relatively movable jaw members for engaging a button therebetween, a feed blade having a longitudinal slot therein, a plate member movable with one of said jaw members, a pin carried by said plate member and engageable with said slot for permitting oscillatory and longitudinal movement of said feed blade relative to said support, and means for oscillating said feed blade about said pin.

18. A buttonhole attachment for sewing machines comprising a supporting plate, an adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade, a pivot pinV slidably and pivotally engaging said feed blade. and means carrying said pin for movement with said adjusting member thereby to change the amount of pivotal movement of one end of said feed blade for a given amount of pivotal movement of the other end of said blade.

19. A buttonhole attachment for sewing machines comprising a support, an adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade having a pair of longitudinally spaced slots, a pivot pin movable with said adjusting member and slidingly engageable in one of said slots for adjustably setting the pivot point of said blade, a pivotal lever carrying a pin slidingly engageable in'said other slot, means for oscillating said lever a predetermined. amount, andy means for moving said feed said shaft for rotation therewith, and pivotally mountedr cam follower means engageable with said cam and said pivot pin for shifting said pivot pin from one position to another.

2l. A buttonhole attachment for sewing machines.

comprising a supporting plate, an adjustingmember positionableV in accordance with the size of button for which the hole to be formed is intended,` a pivot pin carried. by said adjusting member and movable. therewith, a feed blade slidably and pivotally engaged with said pivot pin, means for oscillating said blade about said pivot pin, means for moving said blade longitudinally of said supporting plate including articulated link means, means interconnecting said adjustable member with said link means to vary the fulcruming of said link means, and means operable by said adjustable means to control, the rate of movement of said means for moving said blade longitudinally.

22. A buttonhole attachment for sewing machines' comprising a support, an adjusting member positionable according to the size of buttonhole desired, a pivot adjustably mounted on the support, a feed blade mounted on the pivot for oscillatory and longitudinal sliding movement relative to said support, means associated with saidr adjusting means for varying the position of the pivot,l

variable actuating means for moving the blade longitudinally, and further means associated with said adjusting member for varying the actuating means to vary thev amount of longitudinal movement of said blade.

23. A buttonhole attachment for sewing machinescomprising a support, an adjusting member positionable according to the size of buttonhole desired, a feed blade,

pivot means for said blade movable with said adjusting member to adjust the pivot point of said blade in accordance with the setting of said adjusting member, means for moving said feed. blade longitudinally relative to said support including an oscillatory arm and a link member having an adjustable pivot point, means associated with said adjusting member for limiting oscillatory movement of said arm to control the rate of longitudinal movementl of said blade, means associated with saidv adjusting member for adjusting the pivot point of said blade to change the fulcrtuming of said link member and thus the longitudinal distance through which said blade may move, a lever for oscillating said feed blade, a pivot pin about which said lever pivots, andV means associated with said longitudinal blade moving means for shifting said pivot pin from one position to another.

24. In a buttonhole attachment for a sewing machine having a needle bar, a horizontal supporting plate, an.

adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade, a pin carried by said adjusting member in pivotal and sliding engagement with said feed blade, an actuating lever adapted to be pivoted in a substantially vertical plane by said needle bar and having a cam finger adjacent one end, a substantially vertical. shaft, oscillatory means for intermittently rotating said` shaft in one direction including an arm engageable by said cam finger, a mutilated pinion fixedly positioned on said shaft,

a rack member having an oblong opening provided withV opposed teeth along the sides of said opening and blankl ends, said mutilated pinion being engageable with said teeth to first move said rack member in one longitudinal direction and then in the other, link means articulatively connected to said rack member and said feed blade including a link element provided with a slot therein, pivotal lever means having a portion thereof in engagement with said adjusting member and including a pin in engagement with the slot of said link element to adjust the fulcruming of said slotted link in accordance with the position of said adjusting member, an eccentric cam carried by said pivotal lever means engageable with the arm of said oscillatory means to control the degreeV of oscillation of said armtin accordance with the position of said adjusting member, a substantially semi-circular cam fixed on said shaft for rotation therewith, pivotally mounted cam follower means engageable with said cam at one end and carrying a pin at its other end, a swivel lever pivoted about said last named pin and engageable at one end with said feed blade to impart oscillatory movement thereto, a follower mounted at the other end of said swivel lever, and a cam roll rotatable by said actuating lever, said cam roll having a zig-zag circumferential groove into which said last named follower projects for oscillating said swivel lever.

25. In a buttonhole attachment for a sewing machine having a needle bar, a horizontal supporting plate, an adjusting member positionable in accordance with the size of button for which the hole to be formed is intended, a feed blade having longitudinally spaced slots, a pin carried by said adjusting member in pivotal and sliding engagement with said feed blade, an actuating lever adapted to be pivoted in a substantially vertical plane by said needle bar and having a cam finger adjacent one end, a substantially vertical shaft, oscillatory means for intermittently rotating said shaft in one direction including an arm engageable by said cam linger, a mutilated pinion iixedly positioned on said shaft, a rack member having an oblong opening provided with opposed teeth along the sides of said opening and blank ends, said mutilated pinion being engageable with said teeth to first move said rack member in one longitudinal direction and then in the other, link means artculatively connected to said rack member and said feed blade including a link element provided with a slot therein, pivotal lever means having a portion thereof in engagement with said adjusting member and including a pin in engagement with the slot of said link element to adjust the fulcruming of said slotted link in accordance with the position of said adjusting member, an eccentric cam carried by said pivotal lever means engageable with the arm of said oscillatory means to control the degree of oscillation of said arm in accordance with the position of said adjusting member, a substantially semi-circular cam Xed on said shaft for rotation therewith, pivotally mounted cam follower means engageable with said cam at one end and carrying a pin at its other end, a pivot pin movable with said adjusting member and slidingly engaged in one of said slots of said feed blade to provide an adjustable pivot point therefor, a swivel lever pivoted about the pin carried by said cam follower and slidingly engaged with said other slot of said feed blade for imparting oscillatory movement to said blade, a follower mounted at the other end of said swivel lever, and a cam roll rotatable by said actuating lever, said cam roll having a zig-zag circumferential groove into which said last named follower projects for oscillating said swivel lever.

References Cited in the tile of this patent UNITED STATES PATENTS Maechler Oct. 26, 1951 

